Added ability to filter incoming requests

README.md

@@ -149,6 +149,35 @@ The above results in:
 
 ![XML-example](https://raw.githubusercontent.com/Napp/xray-laravel/master/docs/xray-xml-example.png)
 
+## Request filtering
+There might be some requests you wish not to track in Amazon X-Ray. In order to filter out those requests, you can call the `addRequestFilterCallback` function, on the `Xray` facade.
+This function takes a callback as a parameter. The callback takes a `Symfony\Component\HttpFoundation\Request` as a parameter and is expected to return a boolean.
+
+Please note that this function call needs to be done in the `register` function of your `AppServiceProvider`. You should, also, keep the checks relatively simple, since most of the application service providers won't be booted when calling the filtering callbacks.
+
+When LaravelXray is booting, the request is checked against each registered callbacks. If none returns false, the request is captured. Otherwise, it is not.
+
+```php
+use Symfony\Component\HttpFoundation\Request;
+use Napp\Xray\Facades\Xray;
+
+class AppServiceProvider extends ServiceProvider
+{
+    /**
+     * Register any application services.
+     *
+     * @return void
+     */
+    public function register()
+    {
+        Xray::addRequestFilterCallback(function(Request $request) {
+            /* some conditions */
+            return true;
+        });
+    }
+}
+```
+
 ## Daemon support
 
 The X-Ray daemon is automatically run in a Lambda environment. Use this over the default `Napp\Xray\Submission\APISegmentSubmitter` to relay requests to Amazon X-Ray.

src/Facades/Xray.php

@@ -23,6 +23,7 @@
  * @method static void initCliTracer(string $name)
  * @method static void submitHttpTracer($response)
  * @method static void submitCliTracer()
+ * @method static void addRequestFilterCallback(callable $callback)
  *
  * @see \Napp\Xray\Xray
  */

src/Xray.php

@@ -13,9 +13,12 @@ class Xray
 {
     private $collector;
 
+    private $requestFilterCallables;
+
     public function __construct(SegmentCollector $collector)
     {
         $this->collector = $collector;
+        $this->requestFilterCallables = [];
     }
 
     public function tracer(): Trace
@@ -82,4 +85,20 @@ public function submitCliTracer(): void
     {
         $this->collector->submitCliTracer();
     }
+
+    public function addRequestFilterCallback(callable $callback): void
+    {
+        $this->requestFilterCallables[] = $callback;
+    }
+
+    public function shouldCaptureRequest(Request $request): bool
+    {
+        foreach ($this->requestFilterCallables as $requestFilterCallable) {
+            if (! $requestFilterCallable($request)) {
+                return false;
+            }
+        }
+
+        return true;
+    }
 }

src/XrayServiceProvider.php

@@ -42,6 +42,12 @@ public function boot()
             return;
         }
 
+        $xraySingleton = $this->app->make('xray');
+
+        if (! $this->app->runningInConsole() && ! $xraySingleton->shouldCaptureRequest($this->app->make('request'))) {
+            return;
+        }
+
         $this->registerCollectors();
     }
 

tests/Facades/XrayTest.php

@@ -0,0 +1,95 @@
+<?php
+
+namespace Napp\Xray\Tests\Facades;
+
+use Napp\Xray\Collectors\SegmentCollector;
+use Napp\Xray\Xray;
+use Symfony\Component\HttpFoundation\Request;
+use PHPUnit\Framework\TestCase;
+
+class XrayTest extends TestCase
+{
+    public function test_it_should_register_request_filtering_callback() {
+        // given an Xray object
+        /** @var Xray $xrayObject */
+        $xrayObject = new Xray(new SegmentCollector());
+
+        // and a mock of a callback to check if the current request should be captured.
+        $callbackCalled = false;
+        $requestCapturingCallbackMock = function(Request $request) use (&$callbackCalled) {
+            $callbackCalled = true;
+        };
+
+        // and the callback has been registered on the facade as a filter callback
+        $xrayObject->addRequestFilterCallback($requestCapturingCallbackMock);
+
+        // when checking, on the facade, if the request should be captured
+        $request = new Request();
+        $xrayObject->shouldCaptureRequest($request);
+
+        // then the callback should have been called
+        $this->assertTrue($callbackCalled);
+    }
+
+    public function test_it_should_return_true_when_no_request_filter_callable_returns_false() {
+        // given a xray object
+        /** @var Xray $xrayObject */
+        $xrayObject = new Xray(new SegmentCollector());
+
+        // and some request filter callback that return true
+        $givenRequestCallbackCount = 3;
+        for($i = 0; $i < $givenRequestCallbackCount; $i ++) {
+            $xrayObject->addRequestFilterCallback(function() {
+                return true;
+            });
+        }
+
+        // when checking, on the facade, if the request should be captured
+        $request = new Request();
+        $result = $xrayObject->shouldCaptureRequest($request);
+
+        // then it should return true
+        $this->assertTrue($result);
+    }
+
+    public function test_it_should_return_false_if_at_least_one_request_filter_callback_returns_false() {
+        // given a xray object
+        /** @var Xray $xrayObject */
+        $xrayObject = new Xray(new SegmentCollector());
+
+        // and some request filter callback that return true
+        $givenRequestCallbackCount = 3;
+        for($i = 0; $i < $givenRequestCallbackCount; $i ++) {
+            $xrayObject->addRequestFilterCallback(function() {
+                return true;
+            });
+        }
+
+        // and one request filter callback that returns false
+        $xrayObject->addRequestFilterCallback(function() {
+            return false;
+        });
+
+        // when checking, on the facade, if the request should be captured
+        $request = new Request();
+        $result = $xrayObject->shouldCaptureRequest($request);
+
+        // then it should return false
+        $this->assertFalse($result);
+    }
+
+    public function test_it_should_return_true_if_no_request_filtering_callback_are_defined() {
+        // given a xray object
+        /** @var Xray $xrayObject */
+        $xrayObject = new Xray(new SegmentCollector());
+
+        // and no request filtering callback defined
+
+        // when checking, on the facade, if the request should be captured
+        $request = new Request();
+        $result = $xrayObject->shouldCaptureRequest($request);
+
+        // then it should return true
+        $this->assertTrue($result);
+    }
+}